UC2854A中文资料具有 16V/10V UVLO、适用于 50Hz 至 400Hz 线路频率、温度范围为 –40°C 至 85°C 的增强型双极性 CCM PFC 控制器数据手册TI规格书

描述 Description

The UC3854A/B products are pin compatibleenhanced versions of the UC3854. Like the UC3854, these products provide all of the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the ac input line current waveform to correspond to the ac input line voltage. To do this the UC3854A/B uses average current mode control. Average current mode control maintains stable, low distortion sinusoidal line current without the need for slope compensation, unlike peak current mode control. A 1%, 7.5-V reference, fixed frequency oscillator, PWM, voltage amplifierwith soft-start, line voltage feedforward (VRMS squarer), input supply voltage clamp, and over current comparator round out the lilst of feataures. Available in the 16-pin N (PDIP), DW (SOIC Wide), and J (CDIP) and 20-pin Q (PLCC) package. See Ordering Information table for availability by temperature range.The UC3854A/B products improve upon the UC3854 by offering a wide bandwidth, low offset current amplifier, a faster responding and improved accuracy enable comparator, a VREF GOOD comparator, UVLO threshold options (16 V/10 V for offline, 10.5 V/10 V for startup from an auxiliary 12-V regulator), lower startup supply current, and an enhanced multiply/divide circuit. New features like the amplifier output clamps, improved amplifier current sinking capability, and low offset VAC pin reduce the external component count while improving performance. Improved common mode input range of the multiplier output/current amplifier input allow the designer greater flexibility in choosing amethod for current sensing. Unlike its predecessor, RSET controls only oscillator charging current and has no effect on clamping the maximum multiplier output current. This current is now clamped to a maximum of 2 × IAC at all times which simplifies the design process and provides foldback power limiting during brownout and extreme low line conditions.

特性 Features

• Controls Boost PWM to Near-Unity Power Factor
• Limits Line Current Distortion To AC Offset (Eliminates External Resistor), 0 V to 5 V Multout Common-Mode Range
• VREF GOOD Comparator
• Faster and Improved Accuracy ENABLE Comparator
• UVLO Options (16 V/10 V or 10.5 V/10 V)
• 300-µA Start-Up Supply Current

简介

UC2854A属于集成电路（IC）的PFC（功率因数校正）。由TI制造生产的UC2854APFC（功率因数校正）功率因数校正 (PFC) 是用于调整交流电路中的电压和电流之间的相位角，使之趋近于零的半导体器件。不同模式包括平均电流、边界导通、连续导通、临界导通、电流控制式频率折返、不连续和不连续导通，开关频率从 6 kHz 至 1.7 MHz 可调。